Recoil-absorbing device for firearms



` Dec. 22, 1936. N. GALLloT RECOIL ABSORBING DEVICE FOR FIREARMS Filed NOV. 22, 1934 2 SheebS-Slueil 1 whiny."

Dec. 22, 41936. N, GALLlQ-f 2,065,273

RECOL ABSORBING DEVICE FOR FIREARMS x Filed NOV. 22, 1934 2 Sheets-Sheet 2 fvy.

Patented Dec. I22, 1936 PATENT OFFICE RECOVIL-ABSORBING DEVICE FUR FIREARMS Norbert Galliot, Vaucresson, France y Application november zz, 1934, serial No. '154mg In France December 5, 1933 '8 Claims. (Cl. 89-14) The present invention relates to improvements in recoil-absorbing devices for firearms, of the type comprising one or more convergent-divergent nozzles, fixed to the extremity of the barrel of the weapon, along the axis of the latter and intended to increase the kinetic energy of the gases, which are thereafter diverted and rejected to the exterior by means of a xeddeflector-system, single or multiple, generated by the revolution of one or more arcs around the longitudinal axis of the weapon.

The invention has for its object to improve the eiciency of these devices from the point of view of the deadening of the recoil, the reduction of the noise and iiash produced by the explosion, the protection of the operator against the gases rejected by the apparatus, (and) the cooling, and to facilitate the construction and assembly.

The drawings attached hereto represent by way of example forms of carrying ,out the invention.

Fig. 1 is an axial longitudinal sectional elevation of one of these forms of carrying out the recoil-absorbing device.

Fig. 2 represents separately a detail of Fig. 1.

Fig. 3 is an axial longitudinal sectional elevation,

' with parts in side elevation, of a gun provided with this device, the latter being shown in dotted outline.

Fig. 4 is a view, partly in axial longitudinal sectional elevation and partly in side elevation of another form of construction.

Fig. 5 is a vertical cross section along line 5-5 of Fig. 4.

In Fig. 1, a designates the barrel of a firearm, b a convergent-divergent nozzle screwed to the front extremity of the barrel, and c a second convergentdivergent nozzle, mounted in front of the latter; d is an obturator, mounted in front of this nozzle c and comprising a channeled cylindrical axial conduit d1 for the passage of the projectile; e designates a casing surrounding the nozzles; f designates an annular passage or throat, generated by the revolution around the longitudinal axis :t-:c of the barrel of the weapon, of the parabolic profile of the rear face c2, turned towards the weapon, of the second nozzle c; g designates a second annular passage or throat, generated by the parabolic prole of the rear face d,Z of the obturator d and of the casing e; these passages or throats f and g constitute in some respect fixed ldeector systems. Arms or partitions h connect the first nozzle b, externally of the latter, to the casing e, and similar arms or partitions i connect the casing to the second nozzle c, externally of the latter; openings are thus provided between these arms or partitions for the passage of the explosion gases, which are diverted and rejected towards the exterior through the annular passages or throats f and g, after they have come to strike the rear faces c2 and d2 of the nozzle c and obturator d, with their maximum momentum as a result of their expansion in the two nozzles b and c successively.

A portion of the gaseous stream leaving the barrel of the firearm, already revolves on itself,

asa result of the riding-grooves in the interior of the barrel, following the pitch of this rifling, like the projectile itself. 'I'his gaseous mass, passing through the nozzles b and c, then into the deector systems f and g, continues to revolve on itself in a direction and along a pitch, corresponding to the riiling of the interior of the irearm. The arms or partitions h and i possess a tapering section and are arranged helically and present a pitch determined according to the pitch of the riding-grooves in the interior of the weapon, so as to offer the minimum of resistance to the helicoidal motion of the gaseous currents at their exit from the absorber, to keep it up and to accelerate it if necessary; but their pitch is opposite to that of the riding-grooves in the interior, left-handed when that of the grooves is right-handed and vice versa.

The nozzles b and c are ried in the same direction as the riiiing of the interior of the weapon, but with a shorter pitch, so as to impress on the gases traversing this nozzle a helicoidal motion of rotation around the axis of the nozzles, in order to produce a series of phenomena suited to increasing the eiiiciency of the brake, in particular by the rarefaction of the central portion of the gaseous stream and its concentration at the periphery, in the course of passage in the nozzles.

According to the invention, the nozzles b and c comprise internally riing grooves leaving between them thin helicoidal partitions b1 and c1 respectively; these partitions have a pitch of the same direction, preferably more rapid than that of the grooves in the interior of the weapon. These helicoidal partitions b1 and c1 are intended to centrifuge the greatest possible portion of the gases; in effect, under the centrifugal action, the gaseous stream tends to be carried towards the internal wall of the noggles b and c while the central portion of this gaseous stream is rarefied.

These partitions b1 and c1 are extended forward up to a little beyond the planes y-y and z-z normal to the axis :zz-:c of the Weapon (and) passing through the lips of the nozzles b and c, so as to obviate the projection into the deflector systems f and g of accumulations of unburnt powder or fragments of projectile driving bands.

The partitions or ribs b1 and c1 serve likewise to coolthe gaseous mass and thus obviate the deterioration of the defiector-systems as a result of the high temperature of this mass.

The partitions or ribs b1 and cl extend radially towards the axis of the weapon only to a distance such that the projectile can never come in contact with them, whatever be its balancing at the exit from the barrel a. For example, the free internal space between these partitions is 1.2 calibres in the case of a 120 mm. gun; it depends in each case on the calibre of the weapon and on the degree of instability of the projectile.

The gaseous stream tapped off by the first nozzle passes out through the rst deflector system f; the remainder leaves for they most part by the second deflector-system g; only a very small fraction escapes by the axial conduit d1 of the obturator d.

Ithas been ascertained that the working zone of each deector-system is considerably increased by the centrifugal action and that the discharge of the gases in this case is not subjected to braking if the deilector-system is given a shape such that the distance from the lip of the ozzleto the curve gradually diminishes slightly in proportion as the arc (generating the deflector by rotation aroundV the axis :v -3:) gets away from this axis, that is to say if this arc approaches the lip of the nozzle. 'I'his arc may terminate in the plane (y-y or z-z) normal to the axis :1r-x of the weapon, passing through the lip of the nozzle (b or c). This arrangement allows a considerable reduction of the diametrical dimensions of the recoil-absorbing device; for example, `for a gun of 120 mm. calibre, the absorber presents a diameter less than 3 calibres.

'I'he casing e is fixed upon the proled external partitions h and i (which present for this purpose a suilicient thickness) of the nozzles b and c by a large number of headed screws or studs i (of which only one has been presented for the facility of the drawings), working in shear; these latter comprise'preferahly a device preventing their loosening. This method of assembly presents the advantage of uniting solidly the casing and the nozzles, of facilitating an exchange of temperature between them, and especially of reinforcing them by one another, thus allowing a considerable gain in thickness and weight.

As represented in Fig. 2, the partitions h and i are set` into one another, which facilitates erection and prevents their relative displacement.

VThe casing e is pierced, in the'region commencing at the rear end of the working portion of the second deflector-system g, with a large number of small'ports el of the diameter sufiiciently small for the gases, escaping violently into the atmosphere through these ports at their exit from the deflector-system g to be suiciently rapidly braked and cooledby the ambient air to be inoensive. These ports e1 are inclined (in the plane of Fig. 1) along the diagonal of the parallelogram of forces, determined by the momentum of the gaseous stream and the centrifugal force on the latter, at the exit from the deilector g; these lports e1 are likewise inclined (in a plane normal to the axi's :vof the weapon and passing through the origin of each of these ports) at an angle which depends on the pitch of the partitions i. It follows from this arrangement that the gaseous jets, which are discharged rearwards with a certain momentum and a certain pressure due to the action of centrifugal force, escape in a direction corresponding to the resultant of these various components and that they do not exert upon the wall of the ports any thrust towards the rear and that they tend to continue in the atmosphere their helicoidal trajectory. By way of example, it will be mentioned that good results have been obtained with ports of a diameter of 2 mm. and a rearward inclination of 50 and a transverse inclination of These ports el, by discharging into the atmosphere, starting from the exit from the ilrst deector-system g, a considerable portion of the gases, allow of reducing the diameter of the absorber device, as a result of the decrease of the section oi' passage necessary between the nozzles and the casing. The gases which have not left through the ports e1 continue their travel towards the rear in a collector tube or rst expansion vessel 1c, following after the absorber device` In the form of construction represented (Figs. 1 and 3), the tube k is cylindrical and disposed concentrically of the barrel a, so that in consequence of the slight external conicity of the barrel a, the first expansion vessel chamber is of tronconical shape and gradually decreases in section towards the rear of the fire-arm. The tube Ic is xed upon the partitions h of the ilrst nozzle b, at their rear extremity, by screws or studs similar to the screws a', and is supported and centred, near its other extremity, by screws or pegs (not represented) upon the external surface of the barrel a (Fig. 3).

Under the iniiuence of centrifugal force, due to the passage of the gases between the helicoidal external partitions of the nozzles, and eventually to this gradual decrease of section of the expansion vessel k, the gases leave partly through ports k1, similar to the ports e1 in the absorber casing e; some of these ports k1 are represented, but it is quite undertood that their number and their orientation must be determined in each particular case.

'I'he iirst expansion vessel or tube 1c opens, through an annular gap k2, at its rear end, into a second collector l of larger diameter, forming a return vessel; the latter can, as represented, be integral with the cradle m of the gun, carrying the trlmnions mi; tightness, at the closed end of this return chamber l, is ensured by rings or any other suitable joint packing l1. The gases reaching the end of the vessel l are, after a slight compression, sent back forwards and escape towards the front through the annular gap lc. They thus encounter the gases discharged through the ports k1 and e1 and retained in proximity to the weapon by their sifting and braking in the atmosphere; they push them back towards the front. 'Ihis return vessel l may be pierced with ports, which will preferably be inclined towards the front and which may be opened out at their ends in nozzle form. The recoil-absorbing device may be provided with a suitable'cooling system; this latter consists (Fig. 1) in a cavity n, formed in the second nozzle c and connected by a union n1 and piping 'n2 to a reservoir of cooling liquid, which is atomized upon the rst deflector-system by ports n3 delivering on the rear face c2 of the second nozzle c. 'I'he cooling liquid may be delivered into the cavity n, for example by a suction and force pump, actuated by the reciprocation of the gun upon its?,l slide for elastic braking (as represented in Fig. 3). This atomization of cooling liquid will take place preferably -after the passage of the gases, at the moment of the return of the piece into firing position, when it is a case of a piece with elastic braking,or under the action of the gases, drawn from the gas tapping or again from any other driving source,-or again at the moment of the return to operating position of the mechanism in automatic firearms not provided with elastic braking.

The cooling liquid thus atomized is carried along by the gases of the following discharge, after having absorbed, during an appreciable time, a certain quantity of heat from the (recoil) absorbing deviceand from the one-or more expansion and return vessels and after having thus cooled the front portion of the gun. The consumption of liquid is very small.

The construction, such as described and represented, allows easy assembly, as Well as the replacement of one or other of the parts without sacrificing any others, for example the casing, or the first or second nozzle with its partitions.

Figs. 4 and 5 represent another modification, corresponding to the application of the invention to an automatic gun of 25 m/m.

As representedin Fig. 4, the recoil-absorbing device comprises four nozzles b and c, c, c, provided With internal ribs b1 and cl and external ones h.y and as in the preceding form of construction; the second and third nozzles are provided With a cooling device` 'n nl n*l n.3. The deector systems f and g present substantially the same arrangement as that described previous'y.

But the ports e1 and k1, in the casing e and in the first expansion vessel are suppressed, in order to avoid the slight iiash which may result from them, and also, when the powder is not absolutely smokeless, the production of a slight fog around the gun and in front of it, which fog might interfere with the sighting. The gases leaving the external partitions h of the first nozzle b, penetrate into a vessel or collector o, presenting a transverse section of volute shape, arranged around the barrel c of the piece; the barrel is Aprovided with a jacket a1 comprising helicoidal ribs a2, determined in the same wa" as the external partitions of the nozzles.

At the front part of the collector o, that is to say near the recoil-absorbing device, there open g into the collector o cooling liquid supply passages,

constituted by channels p formed on the outer surface of the barrel a (or on the inner face of a jacket shrunk upon the barrel); these channels p are fed with liquid by a tank q xed upon the barrel at the rear of the latter. The liquid is4 conveyed to this tank by a union q1 to which is connected the piping n2 serving for the cooling of the absorbing device. v

The gas-tapping jacket r of the gun considered, situated between the volute collector s and this reservoir tank q, is insulated from these latter by packing rings r1 and a jointing gasket r2, of any suitable construction. The grooves p for supply of liquid are arranged so as not to coincide with the gas tapping.

The gases (and the atomized and vaporized liquid) are animated with a helicoidal motion in the volute o, kept up and preferably accelerated by the ribs a2 of the jacket a1 of ,the barrel, and leave the volute, in the form of a sheet, passing between partitions o1 arranged obliquely according to the pitch of the helicoidal rotary motion of the gaseous mass in the volute. To the outlet from the volute there can be fitted -a collector in the shape of a cone or nozzle o2, connected to a flexible or rigid piping which carries the gases either behind the gun, or into a vessel or collector placed in any suitable position. I

It is quite understood that the cooling means of the recoil-absorber and gun may be omitted. their use being advantageous only for weapons firing at a very rapid rate or subject for any other reason to great heating.

In the case where loss of the cooling liquid cannot be countenanced, the latter can be recovered by leading the exhaust gases, by means of the piping connected to the volute o, into a collecting vessel which plays at the same time the part of condenser.

What I claim is:

1. A recoil absorbing device for firearms, comprising in combination a number of convergentlution of arcs around the axis of the gun and adapted to deflect and reject the gases to the exterior, together with a number of thin and radially short internal helicoidal partitions, provided upon the internal surface of said nozzles and spaced from the axis of the gun by a distance such that the projectile can never come in contact with said partitions.

2. A recoil absorbing device for firearms, comprising in combination a number of convergentdivergent nozzles. fixed to the end portion of the barrel of the gun, along the axis of the latter and adapted to increase the kinetic energy of the gases,al fixed blade system, generated by the revolution of arcs around the axis of the gun and adapted to deiiect and reject the gases to the exterior, together with a number of thin and radially short internal helicoidal partitions, provided upon the internal surface of said nozzles, extending forwards as far as a little beyond the plane passing through the lip of the respective nozzle, normally to the axis of the gun, and spaced from the axis of the gun by a distance such that the projectile can never come in contact with said partitions.

3. A recoil absorbing device for firearms, comprising in combination a number of convergentdivergent nozzles, fixed to the end portion of the barrel of the gun, along the axis of the latter and adapted to increase the kinetic energy of the gases,-a xed blade system, generated by the revolution of arcs around the axis of the gun and adapted to deflect and reject the gases to the exterior, the cross section of each deflector system for the passage of the gases being substantially constant, and the distance from the deflector system to the lip of the nozzle decreasing gradually in proportion to the distance of the arc, generating the deflector, from the axis of the gun.

4. A recoil absorbing device for firearms, comprising in combination a number of convergentdivergent nozzles, fixed to the end portion of the barrel of the gun, along the axis of the latter and adapted to increase the kinetic energy of the gases,a fixed blade system, generated by the revolution of arcs around the axis of the gun and adapted to deflect and reject the gases to the exterior, helical partitions arranged externally upon the nozzles. and a substantially tubular casing secured to said partitions and enclosing the lzo whole of the nozzles and pf the blade system, said casing being provided with ports of small diameter, starting at a certain distance from the forward end of the casing and adapted to allow the escape of a portion of the gases therethroughA to the exterior. said ports being inclined in a direction corresponding on the one hand to the resultant of the momentum oi the gases and of the action of centrifugal force, and on the other hand to the pitch of the helicoidal motion communicated to the gases by the external partitions of the last nozzle.

5, `A recoil absorbing device i for rearms, comprising in combination a number of convergent-divergent nozzles, ixed to' the end portion of the barrel of the gun, along the axis of the latter and adapted to increase the kinetic energy of the gases,-a ilxed blade system, generated by the'revolution of arcs around the axis o! the gun and adapted to deect and reject the gases to the exterior, helical partitions arranged externally upon the nozzles, and a substantially tubular casing secured to s'aid partitions and enclosing the whole of the nozzles and of f the blade system, said casing 4being provided with ports of small diameter, starting at a certain distance from the forward end of the casing and adapted to allow the escape of a portion of the gasestherethrough to the exterior, together with a rst expansion vessel, mountedgaround the barrel of the gun, in the rear of said casing, and provided with ports for the escape of a part of the gases, and a second expansion vessel, adapted to return the gases forwards.

6. A recoil absorbing device for rearms, comprising in combination a number of convergent-divergent nozzles, fixed to the end portion of the barrel oi' the gun, along the axis of the latter and adapted to increase the kinetic energy o! the gases,-a fixed blade system, generated by the revolution of arcs around the axis oi the gun and adapted to deflect and reject the gases to the exterior, together with a cavity provided in one of the nozzles, piping means for conveying a cooling liquid into said cavity and ports extending from said cavity into the deflector system, where the cooling liquid is carried along with the gases.

7. A recoil absorbing device for firearms, comprising in combination a number of convergent-divergent nozzles, fixed to the end por-v tion of the barrel oi the gun, along the axis of the latter and adapted to increase the kinetic energy of the gases,a xed blade system, generated by the revolution of arcs around the axis of the gun and adapted to deflect and reject the gases to the exterior, helical partitions arranged externally upon the nozzles, and a substantially tubular casing secured to said partitions and enclosing the whole of the nozzles and of the blade system, together with a collector, of volute shape, arranged around the barrel of the gun, in the rear of and providing a continuation of said tubular casing and adapted to receive the said gases.

8. A recoil absorbing device for firearms, comprising in combination a number of convergent-divergent nozzles, xed to the end portion of the barrel of the gun, along the axis of the latter and adapted to increase the kinetic energy of the gases,-a ixed blade system, generated by the revolution of arcs around the axis of the gun and adapted to deect and reject the gases to the exterior, helical partitions arranged externally upon the nozzles, and a. substantially tubular casing secured to said partitions and enclosing the whole of the nozzles and of the blade system, together with a collector, of volute shape, arranged around the barrel of the gun, in the rear of and providing a continuation of said tubular casing and adapted to receive the said gases, and with means for conveying a cooling liquid into said collector.

NORBERT GALLIOT. 

